1. Field of the Invention
This invention relates to container filling machinery and particularly to a machine amd method for transferring a predetermined quantity or number of items from an intermediate receptacle to a final container.
2. Description of the Prior Art
My U.S. Pats. No. 3,517,708 issued June 30, 1970; No. 3,621,891 issued Nov. 23, 1971; and No. 3,696,581 issued Oct. 10, 1972 describe rotary-drum machines for filling intermediate receptacles with predetermined amounts of materials for transfer to ultimate containers, and their disclosures are incorporated in this application by reference.
In these prior machines, elongated rake members spaced circumferentially around a horizontal or inclined drum mounted for rotation about its axis each have a plurality of inward-projecting tines for picking up portions of materials such as food products in the bottom of the drum as the drum rotates and for carrying the portions to a predetermined release point near the top of the drum for discharge onto a chute or shaker tray for delivery into a line of intermediate receptacles extending through the drum. The receptacles are fastened to an endless conveyor that includes means for shaking the receptacles as they are filled to eliminate voids and to obtain a uniform packing density in each receptacle corresponding to a predetermined package amount. After being filled, the intermediate receptacles are transported by the conveyor to a separate station outside the drum where their contents are transferred to a line of ultimate containers on a second conveyor that is synchronized with the movement of the receptacle conveyor.
The present invention is directed to an improvement over the transfer apparatus disclosed in my copending application Ser. No. 588,205 filed on June 19, 1975, which is a continuation of application Ser. No. 423,123 filed on Dec. 10, 1973 now abandoned. That application discloses means for delivering a predetermined number of items of substantially uniform size from a drum-type filling machine to a line of containers. The delivery means comprises a plurality of open-bottom intermediate receptacles transported by an endless conveyor from a filling station inside a revolving drum loader to a delivery station outside the drum.
A stationary base plate or deadplate is positioned under the receptacles and extends from the filling station to the delivery station. The receptacles have flat bottoms that rest on and slide over the base plate between the filling and delivery stations; so that no transferred material drops through the open bottoms of the receptacles until the base plate terminates at the delivery station.
The base plate of my prior application ends abruptly at right angles to the line of travel of the intermediate receptacles. It has been found in certain filling situations that sudden delivery of all the materials in an intermediate receptacle may cause the materials to bridge across the opening of the final container below. The bridged material prevents the remainder from entering the container, resulting in short fills and a product cleanup problem at the final fill location. This becomes a particular problem when the final container has a relatively small opening in relation to its capacity or when the product items are angular or irregular in shape.
Another problem arises when several small intermediate receptacles are needed to assure an exact integral multiple count fill in each final container. This situation occurs with items of non-uniform shape or of a statistical size variation great enough to cause an inexact fill in a given transfer receptacle unless it is sized to hold only a predetermined small numer of the items, the small number being an integral fraction of the total count fill desired in the container.
For example, it might be desired to fill a jar With one dozen bouillon cubes, but the largest receptacle pocket that will consistently hold only a predetermined number of cubes may be one that is sized to hold only three cubes. Then four transfer receptacles, or four separate pockets in one receptacle, will be needed to carry the cubes to fill one container. Having only a single transfer position in this situation complicates the synchronization of the receptacle and container lines and also limits the speed of the conveyor line to a fraction of the speed of the receptacle line.
Still another problem results when it is necessary to fill a container having a small opening in relation to its volume, such as a small mouth jar, or a narrow deep box, such as a dry cereal box, with a predetermined amount of loose materials. In order to rapidly fill a transfer receptacle having the appropriate volume, it is desirable to make the receptacle relatively shallow with straight sides. This results, however, in a mismatch between the large opening area of the transfer receptacle and the small opening area of the final container, and some means is required to channel the flow of material from the receptacle to the container to prevent spilling.